The invention relates to exercise devices with a press arm, e.g. for shoulder rotary press and other exercises, and more particularly to improved adjustment therefor.
For exercise equipment with a decline or flat to shoulder rotary pressing station, it is necessary to have a press arm whose starting position can be adjusted. It is also advantageous that no tension be put on the cabling that is linked to a source of resistance, e.g. a weight stack, during any of the starting positions, since this would necessitate a secondary adjustment with the cabling for the weight stack. In the prior art, some manufacturers have put a secondary pivot at some point between the press arm main pivot and the press handle. The pulleys and cables linked to the weight stack are attached at some point between such pivots so that the cable is never put in tension at any starting point. In such arrangement, the distance from the press handles to the main pivot of the press arm changes for each starting position, and because of this, the weight ratio is different for each starting position, which is a disadvantage. More adjustments are sometimes required to the bench and to put the user in the correct position to perform the exercise in such type of system.
In one known attempt to solve the above-noted problem, an adjustable floating link is pivotally connected to the press arm half way between the press handles and the main pivot. A pulley is attached at the bottom of the link by a cable wrapped therearound providing 1:1 resistance. When the press arm is at rest, the link stops somewhere on the frame so that when the press arm is adjusted with the adjustable link, the pulley never changes position. While the resistance profile was the same for all press positions, and the system allowed for minimal adjustments to the bench, this type of press station was not perceived well by consumers. The floating link would tend to swing back and forth when performing chest exercises, and the press station was perceived as unstable.
A known improvement to the above-noted floating pendulum adjustable link press arm adds two more links, one of them being adjustable. In this four bar linkage, two of the links remain stationary, while the press arm (being one of the links) and an adjustable link (being the fourth link) move while the starting position is adjusted. One of the stationary links is typically part of the frame, and the other stationary link is the attachment point for the cable and/or pulley. The press arm can then be adjusted without putting any tension on the cable system, and the distance from the main pivot to the press handles never changes. The disadvantage in this system is that by adding extra pivots for the linkages, more friction is introduced to the mechanism, and more cost.
The present invention accomplishes the above-noted goals without the noted added friction nor the noted added pendulum motion, and with a more cost-effective construction and mechanism. A simplified construction is provided by a frame, a press arm, and an adjustable link. The adjustable link has a pulley over which a cable passes, linking it to the source of resistance, such as a weight stack. The adjustment link is pivotally connected to the press arm between the main pivot and the press handles. The cable wraps around the pulley, which allows for a 1:1 weight resistance relationship with the cable. This is similar to the floating link system described above, except that the pulley on the present adjustable link is guided by a frame member for movement therealong, and in the preferred embodiment rolls thereon. By strategically placing the noted frame member and the coupling directional pulleys on the frame, the direction of force on the linkage causes the linkage pulley to ride on the frame member. The contact of the linkage pulley against the frame stops the adjustable link from floating. When the press arm is at rest, the adjustable link is stopped by and rests on the frame. As it is stopped, gravity pulls the adjustable link rearwardly, disengaging the pulley from contact with the frame. This allows the cable routed over such pulley to be used with a different exercise when the press arm is not in use. The rotation of the pulley caused by the cable is in the same rotational direction caused by it rolling along the frame member. The invention keeps the press handles in the same position relative to the main pivot, and does not introduce additional friction due to more pivots, and produces a stable pressing motion because the adjustment link does not float. The invention also enables economy of manufacture because of fewer parts.